Why is East Africa referred to as the crade of humanity

Because that is where scientists believe the first humans originated from, and where the earliest civilizations started.

the  equal rights amendment  (era) states: "equality  of  rights  under the law shall not be denied or abridged by the united states or by any state on account of sex." congress first introduced the era in 1923, but the campaign for ratification took off in the 1960s during the  civil rightsmovement.